The present invention relates to a device to grind clothing teeth or wires or to clean cylinders in particular in cards with a grinding part with an elastic layer.
From the DE 197 38 187 A1 a device on a card is known, at which the cover surface of a grinding roller is elastic and which engages with slight pressure with the points of the flat clothing. With this, without setting high requirements for the grinding means and its carrier means, an even grinding of the points of the flat clothing is to be maintained. The structure of the roller at said known art is such, in that on a soft-elastic cover of for instance foam material as padding a further cover layer with a grinding material, for instance grinding grains of corundum is being attached. Thereby the cover layer is a carrier consisting of textile material, which is being wound over an inner cover. The textile-type carrier for the grinding means is elastic at least in one direction of the applied fabric or knit material. The weight of the roller itself generates a pressing force by which the roller rests on the clothing.
Thus according to the DE 197 39 187 a hard but flexible outer layer is being provided on a soft-elastic base. By means of the elastic layer according to the known art the grinding means is to adapt itself xe2x80x98to the deviations in relation to different heights of the pointsxe2x80x99. Thereby xe2x80x98single protruding clothing points are to be able to penetrated deeper into the surface and become thereby deformed in such a way, that also the less protruding points come in contact with the grinding surfacexe2x80x99. Thus it is not intended that the single points can penetrate the harder grinding layer. The wear behaviour of this grinding layer is not being described in DE 197 38 187.
In a device according to the known art problems are encountered to meet the requirement of accuracy for the manufacturing of the grinding roller. It is hereby reminded that the roller is of an axial length of at least one meter, whereat during grinding of a clothing only fractions of millimeters of the wire element may be removed. According to the known art the surface of the roller is surposed to be hard and flexible at the same time, whereat it is being fastened onto an elastic base. It is practically impossible to form such a surface without having to take into account certain inaccuracies. The transposition of such inaccuracies onto the clothing would be followed by severe consequences for the carding process. The roller manufacturing process according to DE 197 39 187 would thus have to be devised in a complicated manner in order to minimise the expected inaccuracies. Special requirements are being made necessary for elastic cover as well as for the cover layer. Especially the cover layer needs to be produced of a specific yarn, in order to meet the requirements being set for the layer. Beyond that, damage on the cover layer destroys the entire roller.
Thus the object of the invention is to provide a device which eliminates the above disadvantages and which at the same time allows a structurally simple, however, still precise treatment of a clothing or a roller.
The task is being solved with a device with the characteristic features of the patent claim 1. According to the invention the device for grinding of clothing teeth or wires or for cleaning of cylinders comprises a grinding part with an elastic surface. Thereby the grinding part consists of an elastic layer within which the grinding means are being embedded. Herewith the clothing is being ground. On the other hand, however, the elastic layer and the grinding means are also gradually being torn out from the grinding part. Even though this causes a corresponding wear of the grinding part, however, an always sharp grinding part is being brought into contact with the clothing teeth and thus a very effective grinding performance results. The elastic layer can for instance consist of foam material or fleece material.
During grinding the elastic layer itself is thus exposed to the clothing points. The hardness of this layer in relation to the hardness of the clothing elements can be chosen in such a way, that the wear on the rollers is considerably faster than the wear on the clothing points, for instance five times, preferably ten times faster. Embedding of grinding means within the wearable layer thus ensures that the grinding effect can be maintained over a predetermined time. The inevitable inaccuracies in the formation of the outer layer are not being transmitted to the clothing, but the cover surface of the clothing is rather being pressed onto the surface of the roller. The relatively soft carrier material is being worn off by the contact with the clothing points for a period of time until these points get into contact with the grinding particles being embedded within the carrier material.
The elastic layer is being arranged on a rigid carrier, which is adjustable towards the clothing or the cylinders. The carrier can either be a metal plate or a metal cylinder or it can consist of another hard material, for instance fibre reinforced plastic. The carrier can also be formed in such a way, for instance with ribs, that it is extremely stiff and thus deflection is being prevented during grinding or cleaning. The elastic layer can be applied around the carrier by spray coating, casting, gluing or clamping. It forms the holding means for the single grinding means. As grinding means grindstones may be used, for instance corundum grains or also fibres which have a high resistance towards the clothing teeth or wires. For the cleaning of cylinders less aggressive grinding means may be applied so that the cylinders are not being damaged.
Depending on the type of application different shapes of the grinding parts are preferable. It is thus possible that the grinding part consists of a roller, which moves in or against the circumferential direction of the clothing or of the cylinders to be cleaned. Often a respective relative velocity in relation to the clothing and to the cylinders is of advantage in order to affect a grinding or cleaning.
For some applications it is also of advantage if the grinding part consists of a grindstone. The grindstone is either placed onto the surface of the clothing or the cylinders or it is moved back and forth in axial direction of the clothing or the cylinder. Thereby a grinding effect or cleaning effect respectively results on the clothing or the cylinder.
If the elastic layer consists of a wear material, then the grinding means is gradually torn out of the elastic layer and the elastic layer is also gradually being worn off. Thereby in a particular advantageous way and in the sense of the invention, the grinding means, as soon as they have lost their sharpness, are being removed together with the elastic layer and thus new sharp grinding means are exposed. The elastic layer is thus gradually removed and the diameter of the grinding roller or the height of the grindstone respectively is thereby being reduced continuously. The position adjustment of the grinding part is effected by means of a flexible support through which the grinding part, for instance through its own weight, rests on the clothing or the cylinder. The position of the grinding part may also be adjusted towards the clothing or cylinder, either specifically by means of an additional device or by a weight, whose load is for instance adjustable by means of a lever. In the case of clothing wires on flat bars the grinding part can also be supported fixedly and the flat bar can be pressed against the grinding part by means of spring load.
Preferably the elastic layer encloses the grinding part entirely. Thereby during its rotation the grinding roller will always stay in contact with the clothing or the cylinder and thus achieve a high grinding effect. If the grinding part is a grindstone then it can be used several times by turning it by 90xc2x0.
If the elastic layer on the grinding part is being arranged in the form of segments, then in an advantageous way, an additional cleaning effect of the grinding part will result. The ground off particles of the grinding part as well as of the clothing or the cylinder are being released due to this segmented arrangement of the elastic layer when they reach the end of a segment and thus do not lead to a soiled grinding part. Moreover a different grinding effect on the grinding teeth or wires results, in particular, if the elastic layer in the various segments comprises different thicknesses.
In a specific embodiment of the invention it is of advantage if the elastic layer contains different grinding means. Said different grinding means can either be arranged evenly within the elastic layer or they may be arranged in sorted manner within the segments. Said segments can either be distributed over the longitudinal axis, the circumference or the height of the elastic layer. Thereby special grinding effects are being achieved, for instance in such a way, that the grinding means, which are arranged nearer to the carrier, are coarser and thus provide a certain compensation for the reduced weight of the grinding part. The elastic layer can also be provided with different thicknesses and/or grinding means with respect to its distribution over the operating width. Herewith a specific grinding effect is being reached, for instance in such a way in that specific levels can be adjusted with regard to the clothing points and other levels with regard to the clothing flanks.
The force by which the grinding part presses onto the clothing teeth or wires or onto the cylinder, can be made adjustable in a particular advantageous embodiment of the device. This is for instance realised with a device for a controlled pressure application. A particularly simple embodiment of an adjustable force can be provided in the form of a weight on a lever arm in relation to the grinding part. By changing the length of the lever, the weight can actuate different pressure forces of the grinding part on the clothing or the cylinders.
Preferably the elastic layer is being made up in such a manner that the clothing teeth or wires at least partially penetrate into the elastic layer. Thereby a particular advantageous grinding effect onto the clothing is being achieved, since through this penetration not only the clothing points but perhaps also the flanks are being effected by the grinding meas and thus also being treated. By this a very advantageous form of the ground tooth or wire results, which during further application of the clothing achieves very good carding results.
In particular if the elastic layer is made as a wear layer, it is of advantage, if a suction means is being attached to the device. Thereby the suction means prevents the ground off material from the clothing or from the cylinders to be cleaned, from falling uncontrolled into the machine.